1. Field of the Invention
The present invention relates to a memory medium storing an original date generation program, a memory medium storing an illumination condition determination program, an original data generation method, an illumination condition determination method, and a device manufacturing method.
2. Description of the Related Art
An exposure apparatus which projects a circuit pattern formed on an original (also called a reticle or a mask) onto a substrate such as a wafer by a projection optical system to expose the substrate is used in lithography. A method of increasing the numerical aperture (NA) of the projection optical system, a method of shortening the exposure wavelength λ, and a method of decreasing the k1 factor are known as methods of improving the resolution of the exposure apparatus.
In a typical approach to the method of decreasing the k1 factor, an assist pattern having a size small enough not to resolve it or enough to suppress its resolution is added onto an original on which a pattern to be transferred is formed. The assist pattern is also often called an assist form, assist feature, light intensity adjustment pattern, scattering bar, diffractive bar, assist bar, assist pattern, dummy pattern, correction pattern, dummy, or the like.
Japanese Patent Laid-Open No. 2004-221594 describes, as a problem to be solved, the fact that any optimization method and modeling method which determine an optimum position of an assist pattern on an original have not yet been developed. Japanese Patent Laid-Open No. 2004-221594 proposes a method of generating an interference map based on a TCC (Transmission Cross Coefficient) and an impulse function describing a resolvable feature on the original, and adding an assist pattern onto the original. Unfortunately, the generation of an interference map requires a large amount of calculation because TCC calculation is necessary, resulting in increases in the calculation time and in the required capacity of a computer memory.